Coagulase-negative staphylococci are the most common bacteria found in cultures from the deep portions of hidradenitis suppurativa lesions, as obtained by carbon dioxide laser surgery

The significance of bacterial findings in hidradenitis suppurativa (HS) is controversial. Interpretation of the results of bacteriological examination s from the surface of HS lesions is obscured by the possible contamination of resident skin bacteria. Bacteriological analysis of aspirates from deepe r parts of HS is liable to show low sensitivity. We used a carbon dioxide ( CO2) laser method to evaporate the diseased tissue level by level from the surface downwards, allowing concurrent sampling of bacteriological cultures from each level and thereby minimizing contamination with bacteria from th e level above. In this study, 22 women and three men with a mean age of 35. 3 years and a mean HS duration of 10.6 years were treated with this CO2 las er surgical method. Aerobic and anaerobic cultures from superficial and dee p levels were taken during surgery. The regions treated were axillary in ei ght and perineal in 17 cases. Bacterial cultures were positive for one or m ore specimens from at least one level in all cases and from deep levels in all but three cases. Sixteen different species or subspecies were found. St aphylococcus aureus and coagulase-negative staphylococci (CNS) were the spe cies most frequently found. Peptostreptococcus species and Propionibacteriu m acnes were not uncommon. S. aureus was detected in a total of 14 cases, s ix of which were fi om the deep levels. S. aureus was the sole bacterium is olated in two deep cultures. CNS were found in 21 patients and 16 of these isolates were from the deep levels. In nine of the 16 deep samples CNS were the only bacteria detected. These findings motivate a re-evaluation of the significance of bacteria in the progress of HS and in particular they sugg est that CNS are true pathogens. It is known that foreign bodies aggravate the virulence of the CNS in surgical implants, and an environment which res embles that produced by a foreign body, as found in chronic HS tissue, serv es to intensify the pathogenic properties of CNS in HS.